Flow pipe comprising a water turbine having a variable cross-section

ABSTRACT

It is generally known in relation to hydroelectric power stations that, before the water impinges on the turbine of the hydroelectric power station and there delivers its energy to the turbine, the water flows through a pipe. Depending on the respective nature of the hydroelectric power station that pipe can be a downpipe through which the water flows, according to the respective local factors, in dependence on the fall height and the amount of water. The object of one aspect of the invention is to provide means, by which the flow speed of the water (fluid) can be adjusted in the region of the turbine. In one aspect, a flow pipe, within which is arranged a turbine which, when a fluid flows through the pipe, is caused to rotate, wherein the turbine has a variable cross-section, by means of which the through-flow cross-section within the pipe is variable.

It is generally known in relation to hydroelectric power stations that,before the water impinges on the turbine of the hydroelectric powerstation and there delivers its energy to the turbine, the water flowsthrough a pipe. Depending on the respective nature of the hydroelectricpower station that pipe can be a downpipe through which the water flows,according to the respective local factors, in dependence on the fallheight and the amount of water.

After the water has delivered a part of its energy to the turbine, thewater further flows away into a river.

The turbine of the hydroelectric power station is usually coupled to agenerator, with which the kinetic energy of the turbine is convertedinto electrical energy, the electrical energy then in turn being fedinto a power supply network.

Often a hydroelectric power station has not just one turbine but also aplurality of turbines and the water is fed to various turbines not justby way of a single pipe but by way of a plurality of pipes. Depending onthe respective amount of water arriving suitable control of the amountof water for the individual pipes is then implemented so that an optimumdegree of efficiency is achieved in the hydroelectric power station.

The turbines are each arranged in the downpipe itself or in theprolongation of the downpipe in the flow pipe.

The passage cross-section for the water in the downpipe, also in theregion of the turbine (water impeller) in the flow pipe is fixed in thatcase at predetermined values.

The flow speed of the water in the region of the turbines is in thiscase usually adjusted by the volume flow, that is to say by the amountof water introduced in the downpipe or the flow pipe. Depending on therespective generator moment which is set, it is then possible to takethe desired power from the system.

Now, the object of the invention is to provide means, by which the flowspeed of the water (fluid) can be adjusted in the region of the turbine.

According to the invention that object is attained by a flow pipe havingthe features of claim 1. An advantageous development is recited in claim2 while claim 3 sets forth a hydroelectric power station with the flowpipe according to the invention.

According to the invention the turbine is so equipped that it has avariable cross-section.

As illustrated in the Figure the turbine 4 (water wheel) comprises adisplacement body 1, on which the vanes 5 (rotor blades) of the turbineare mounted on the outside thereof. The turbine 4 with the vanes 5 canrotate in the flow pipe 3 and thus drive a suitably coupled generator(not shown in the Figure).

As can be seen in the illustrated example the cross-section of thedisplacement body is variable. For that purpose the displacement body 1is in the manner of a bellows and is provided with an elastic surface.When now the bellows is supplied from the interior with a suitablepressure which is greater than the external pressure in the flow pipe,the bellows expands and assumes the shape indicated by the broken line2. As the entire turbine is of a circular configuration and that alsoapplies in respect of the bellows, the increased cross-sectional area ofthe displacement body automatically becomes a reduced cross-sectionalarea for the water within the flow pipe 3.

That reduced cross-sectional flow area for the water in the flow pipeautomatically results in an increase in the flow speed so that theentire turbine is driven more rapidly than previously.

Expandability of the displacement body can be embodied by its elasticsurface and, to expand the bellows, it can be provided that a fluid ispumped into the interior of the flow body or the bellows.

Thus, by means of adjustment of the cross-section of the displacementbody, it is also possible for the speed of rotation of the entireturbine to be adapted to a desired value for the respective generator sothat the speed of rotation of the turbine is optimally adapted to thegenerator system and thus the best possible degree of efficiency is alsoachieved.

The measure set forth in accordance with the invention is extremelysimple and nonetheless at the same time highly effective.

The arrangement for arresting and mounting the turbine is not shown inthe Figure, for reasons of clarity thereof.

1-3. (Canceled).
 4. A system comprising: a flow pipe; and a turbinedisposed within the flow pipe and caused to rotate when fluid flowsthrough the pipe, the turbine having an enlargeable cross-section toreduce a cross sectional area for through-flow of fluid within the flowpipe.
 5. The system of claim 4 wherein the enlargeable cross-sectioncomprises an enlargeable cross section to correspondingly reduce thecross sectional area for fluid flow.
 6. The system of claim 4 whereinthe turbine comprises a deformable bellows to enlarge the enlargeablecross section.
 7. The system of claim 6 wherein the deformable bellowshas an elastic surface.
 8. The system of claim 7 wherein the deformablebellows has an Interior to receive fluid having a pressure greater thana pressure outside the deformable bellows.
 9. The system of claim 8further comprising a generator coupled to the turbine, to convertkinetic energy into electrical energy.
 10. The system of claim 4 furthercomprising a generator coupled to the turbine, to convert kinetic energyinto electrical energy.
 11. The system of claim 4 wherein the turbinecomprises a body and rotor blades mounted on the body.
 12. Ahydroelectric power station comprising at least one system as recited inclaim
 4. 13. A method for use in association with a hydroelectric powerstation having a flow pipe, the method comprising: providing a turbinewithin the pipe to receive kinetic power when fluid flows through thepipe; and enlarging a cross-sectional area of the turbine to reduce across sectional area for fluid flowing within the flow pipe.
 14. Themethod of claim 13 further comprising converting the kinetic energy intoelectrical energy.
 15. The method of claim 13 wherein enlarging thecross sectional area comprises enlarging the cross sectional area toincrease a flow speed of the fluid flowing within the pipe to adjust arotational speed of the turbine to a generator system.